Flavorants are frequently added to tobacco products to achieve desirable taste sensations. One of the more common flavorants is menthol due to its mint flavoring and cooling effects that can be imparted to tobacco smoke. However, due to the high volatility of menthol, which causes menthol to vaporize and gradually escape from the tobacco product during storage, controlling the concentration of menthol in a tobacco product is difficult.
The use of menthol is especially problematic when used in tobacco products, such as cigarettes, in combination with sorbent materials. Sorbent materials are generally employed in tobacco products to remove selected constituents of tobacco smoke. The more common sorbent materials include activated carbons and zeolites.
Activated carbons are useful sorbent materials since they have a large adsorbent capacity for a low cost. However, while activated carbons are effective in removing targeted constituents of tobacco smoke, they lack selectivity and can also adsorb flavorants, such as menthol, present in the smoking article. This adsorption of flavorants is not only detrimental to the level of flavoring ultimately passed to an end user of the tobacco product, but is also detrimental to the activated carbon itself. Through adsorbing the flavorant, the activated carbon can become deactivated by the adsorbed flavorants as the adsorbed flavorants can fill available adsorbent sites within the activated carbon reducing the adsorbency of the activated carbon.
Accordingly, there is interest in providing additives, such as flavorants, in tobacco products containing sorbent materials, wherein the additives are protected from sorption by the sorbent materials.